Assessing real world vaccine effectiveness: A review of Scotland's approach to monitoring human papillomavirus (HPV) vaccine impact on HPV infection and cervical disease.

High-risk human papillomavirus (HPV) infections can progress to cervical cancer which is the fourth most common cancer in women globally. In Scotland, the incidence of cervical cancer has a strong socioeconomic deprivation gradient disproportionately affecting women from more deprived areas. An HPV vaccination programme was initiated in Scotland in 2008 targeting girls aged 12-13 years with a catch-up campaign running for the first three years for girls aged up to 18 years. The programme has evolved over the last 16 years with changes in the type of vaccine, dosing schedules and the extension of the programme to boys and gay, bisexual and other men who have sex with men. Vaccine uptake in Scotland has historically been high but has gradually decreased over time and disparities exist in women from more deprived areas of Scotland. The ability to link national immunisation and screening databases in Scotland has allowed direct monitoring of the impact of the HPV vaccine on virological and histological outcomes. Analyses of this linked data have demonstrated real-world evidence of high vaccine effectiveness against HPV infection, cervical disease, and cervical cancer with evidence of herd immunity in unvaccinated women. Continued monitoring is crucial to assess the duration of protection, the impact of vaccine and dosing schedules changes and the emergence of potential type replacement. With the World Health Organisation's aim to eliminate cervical cancer as a public health problem by the next century addressing the inequalities in cervical cancer incidence will be crucial. This will require targeted interventions for women most at risk of cervical cancer to ensure elimination is achieved timely for all women in Scotland.

Exploring the complexity of the implementation determinants of human papillomavirus vaccination in Africa through a systems thinking lens: A rapid review.

A rapid review was conducted to explore the implementation determinants of human papillomavirus (HPV) vaccination in the World Health Organization African Region and describe their dynamic relationship. PubMed and Google Scholar were searched in October 2023 to find relevant literature. A total of 64 published studies that reported factors affecting HPV vaccination were identified. Analysis of identified factors yielded 74 implementation determinants of HPV vaccination across the five domains of the Consolidated Framework for Implementation Research (CFIR): two (2.70%) were in the innovation domain, seven (9.46%) were in the outer setting domain, 14 (18.92%) were in the inner setting domain, 37 (50%) were in the individual domain and 14 (18.92%) were in the implementation process domain. A causal loop diagram of these implementation determinants revealed four balancing and seven reinforcing loops. Applying systems lens promoted a more holistic understanding of the implementation determinants of HPV vaccination, exposing leverage points for interventions.

Human Papillomavirus Vaccination Coverage Among Adolescent Girls Aged 13-17 Years - U.S.-Affiliated Pacific Islands, 2013-2023.

Worldwide, cervical cancer is the fourth most common cancer among women, and the World Health Organization (WHO) Western Pacific Region, where the U.S.-affiliated Pacific Islands (USAPI) are located, accounts for one quarter of all estimated cases. Human papillomavirus (HPV) vaccines are recommended at age 11-12 years to prevent most cervical cancers. HPV vaccines were introduced across USAPI during 2007-2016, predominantly provided through school-located vaccination programs. Retrospective analysis using data from jurisdictional immunization information systems was used to estimate vaccination coverage among adolescent girls as of the last day of each calendar year during 2013-2023. This analysis measured progress toward the WHO 2030 vaccination coverage goal of ≥90% completion of the HPV vaccination series among girls by age 15 years. As of December 2023, initiation of the HPV vaccination series among adolescent girls aged 13-17 years ranged from 58.0% in Palau to 97.2% in the Northern Mariana Islands, and HPV vaccination series completion coverage ranged from 43.4% in Palau to 91.8% in the Northern Mariana Islands. HPV vaccination series completion coverage is >90% in the Northern Mariana Islands and is on track to meet WHO goals by 2030 in American Samoa. Assessment of adolescent vaccination coverage can help immunization programs monitor progress toward regional goals and identify populations and areas with low coverage. Implementing evidence-based strategies to increase vaccine access and coverage would benefit jurisdictions with lagging coverage.

A systematic review of interventions to promote human papillomavirus (HPV) vaccination in Africa.

OBJECTIVE: We conducted a systematic review to assess the scope and effectiveness of interventions to improve human papilloma virus (HPV) vaccination in Africa from 2006 to 2021. STUDY DESIGN: Systematic review. METHODS: Four databases (Medline, Embase, CINAHL and PsycINFO) were searched for articles published between 2006 and 2021. Articles were screened and included based on eligibility criteria using DistillerSR (Version 2.35). Data were extracted and reported using a narrative synthesis. A quality assessment was also conducted for each study using validated quality appraisal tools. RESULTS: Out of 7603 articles identified by a systematic search, 18 articles met the inclusion criteria. Included studies comprised impact evaluation and cross-sectional studies published between 2012 and 2021 and conducted in eight African countries namely: Nigeria, Cameroon, South Africa, Kenya, Tanzania, Zambia, Mali, and Malawi. Study quality ranged from high to low quality. Interventions comprised fifteen educational and three multicomponent interventions. Out of thirteen impact evaluation studies (all educational interventions), twelve studies were effective in increasing HPV vaccine uptake and/or improving participants' knowledge, attitudes, and perceptions about the vaccine. Across five cross-sectional studies (two educational and three multicomponent interventions), HPV vaccine uptake rates ranged from 34% to 93.3%, with a consensus on safety and effectiveness in 67.9%-90.3% of participants post-intervention. CONCLUSION: Educational and multicomponent interventions have been implemented to improve HPV vaccination in Africa. While educational interventions have proven effective at improving HPV vaccine uptake, a more diverse range of interventions with robust impact evaluation study designs are needed to strengthen the available evidence and improve vaccine uptake.

Entenda como o papilomavírus humano (HPV) pode se manifestar

Principal causa do câncer de colo de útero, também relacionado a mais outros cinco tipos de cânceres, a infecção pelo papilomavírus humano (HPV) não apresenta sinais ou sintomas na maioria das pessoas. Assim, o vírus acaba por ser transmitido de forma silenciosa, pelo fato de a pessoa desconhecer que contraiu a infecção. Em alguns casos, o HPV pode ficar latente de meses a anos, sem manifestar sinais visíveis ou apresentar manifestações subclínicas, isto é, detectáveis por exames.

Identification of memory mechanism in tissue-resident stem cells via ANGPTL4 beyond immune cells upon viral antigen exposure.

Although memory functions of immune cells characterized by increased resistance to subsequent infections after initial pathogen exposure are well-established, it remains unclear whether non-immune cells, especially tissue-resident stem cells, exhibit similar memory mechanisms. The present study revealed that detrimental effects of initial viral antigen exposure (human papillomavirus [HPV]) on diverse stem cell functions were significantly exacerbated upon subsequent secondary exposure both in vitro and in vivo. Importantly, endometrial stem cells exhibited robust memory functions following consecutive HPV antigen exposures, whereas fully differentiated cells such as fibroblasts and vesicular cells did not show corresponding changes in response to the same antigen exposures. Deficiency of angiopoietin-like 4 (ANGPTL4) achieved through small hairpin RNA knockdown in vitro and knockout (KO) mice in vivo highlighted the critical role of ANGPTL4 in governing memory functions associated with various stem cell processes. This regulation occurred through histone H3 methylation alterations and PI3K/Akt signaling pathways in response to successive HPV antigen exposures. Furthermore, memory functions associated with various stem cell functions that were evident in wild-type mice following consecutive exposures to HPV antigen were not observed in ANGPTL4 KO mice. In summary, our findings strongly support the presence of memory mechanism in non-immune cells, particularly tissue-resident stem cells.

Human papillomavirus vaccination uptake and determinant factors among adolescent schoolgirls in sub-Saharan Africa: A systematic review and meta-analysis.

Despite the ongoing global vaccination campaign aimed at preventing human papillomavirus (HPV) related health issues, the uptake of the HPV vaccine remains unacceptably low in developing regions, particularly in sub-Saharan Africa (SSA). Therefore, this systematic review and meta-analysis aimed at determining the pooled prevalence and associated factors of HPV vaccine uptake among adolescent school girls in SSA. Electronic bio-medical databases were explored. Pooled prevalence, publication bias, meta-regression, sub-group, and sensitivity analysis were performed. The estimated pooled prevalence of HPV vaccine uptake was 28.53% [95% CI: (5.25, 51.81)]. Having good knowledge and a positive attitude was significantly associated with HPV vaccine uptake in SSA. Subgroup analysis revealed the highest uptake was 62.52% from Kenya and the lowest was 3.77% in Nigeria. The HPV vaccine uptake is low. It underscores the need for community education, school-based immunization, and education programs that promote the uptake of the vaccine to increase coverage.

A systematic literature review of human papillomavirus vaccination strategies in delivery systems within national and regional immunization programs.

The uptake of human papillomavirus (HPV) vaccine remains suboptimal despite being a part of routine vaccination within national immunization program(s). This indicates probable challenges with the implementation of HPV immunization program(s) in various countries. The objective of this systematic literature review (SLR) was to identify implementation strategies for HPV vaccination within national and regional immunization programs worldwide with an aim to provide guidance for countries targeting to increase their HPV vaccine coverage rate (VCR). A comprehensive literature search was conducted across Medline and Embase and included articles published between January 2012 and January 2022. Of the 2,549 articles retrieved, 168 met inclusion criteria and were included in the review. Strategies shown to improve HPV vaccination uptake in the reviewed literature include campaigns to increase community awareness and knowledge of HPV, health care provider trainings, integrating HPV vaccination within school settings, coordinated efforts via multi-sectoral partnerships, and vaccination reminder and recall systems. Findings may help national authorities understand key considerations for HPV vaccination when designing and implementing programs aiming to increase HPV VCR in adolescents.